1. Technical Field
The present invention relates to a device and a method for handling incoming data packets and to a device and a method for assembling and transmitting data packets.
2. Description of the Prior Art
An arrangement combining such devices for realizing the related methods is already known in the art, e.g. from the DAVIC specification 1.0 Rev. 4.1 Part 08: "Lower Layer Protocols and Physical Interfaces", p 85-89, which relates to a set top box for, in one direction, receiving ATM cells on an input terminal coupled to an ATM input bus. This set top box includes a first unit denoted as network interface means unit, NIU, and a second unit denoted as set-top unit, STU. Both units are interconnected by means of an interface means consisting of several buses as can be seen from the figure on p 87 of the mentioned prior art reference. Among these buses a bi-directional Data bus serves to transport ATM-cells from the first unit towards the second unit whereas an I2C bus transports control information between the first unit and the second unit. The second unit STU further includes a module called "slow" SAR module intended for ATM layer and ATM-adaptation layer termination of the ATM cells entering the second unit. Part of this module thus corresponds to the information extraction unit mentioned in the preamble of claim 1 and which was adapted to extract user and header information of incoming data packets. However not all ATM-cells need to be terminated in this second unit STU. In the prior art solution some predetermined cells, being Physical Layer Operation And Maintenance cells related to the first unit NIU and ATM cells carrying MPEG stream, need to be terminated in this first unit. This is realized by the presence of another SAR module included within the first unit, denoted "fast" SAR on the fig on p 87 of the mentioned prior art reference. The function of this fast SAR module is similar to the function of the slow SAR module, except that this fast SAR module also performs a selection on the incoming ATM-cells, thereby selecting these predetermined cells for further ATM and ATM adaptation layer termination within the first unit, while sending all other incoming ATM cells except these predetermined cells, via the bi-directional Data bus towards the second unit.